Pilot valve assembly for a switch heater

ABSTRACT

A pilot valve assembly for use with a railroad switch heater that resists sooting and blowout, and includes a burner nozzle, circular in cross section, and a shield and deflector unit mounted on the burner nozzle. The shield portion of the shield and deflector unit is square in cross section and extends from the burner nozzle terminating in a flame discharge opening. A deflector portion extends over the flame discharge opening and covers about one-third of the area opening.

United States Patent Stikkers et al.

[54] PILOT VALVE ASSEMBLY FOR A SWITCH HEATER [72] Inventors: Alexander P. Stilrkers, Elgin; Albert E. Elzy, Algonquin; Joseph L. Czyl, Glenview, all of 111.

[73] Assignee: Vapor Corporation, Chicago, 111.

[22] Filed: Oct. 29, 1970 [21] Appl. No.: 85,090

[52] US. Cl. ..l26/27L2 B, 431/278, 431/350 [51] Int. Cl ..F23c 5/00, F 23q 9/00 [58] Field of Search ..126/271.2 B; 431/278, 350,

[56] References Cited UNITED STATES PATENTS 2,776,001 1/1957 Goulding, Sr ..431/352 X [151 3,692,016 [451 Sept. 19,1972

3,122,195 2/1964 Kimmel et al ..431/278 X 3,297,074 1/ 1967 Murphy ..431/350 X 3,302,687 2/1967 Gjerde ..431/350 X 3,439,161 McElwee et al..126/271.2 BX

Primary Examiner-Charles J. Myhre Attorney-Julian Falk [57] ABSTRACT A pilot valve assembly for use with a railroad switch heater that resists sooting and blowout, and includes a burner nozzle, circular in cross section, and a shield and deflector unit mounted on the burner nozzle. The shield portion of the shield and deflector unit is square in cross section and extends from the burner nozzle terminating in a flame discharge opening. A deflector portion extends over the flame discharge opening and covers about one-third of the area opening.

9 Claims, 11 Drawing Figures PA'TENTEDSEP 9 I972 'SHEET 1 BF 4 Inve rzl'o rs ALEXANDER P. STIKKERS ALBE m" E. ELZY PATENTED E 1 9 I973 SHEET 2 [IF 4 Inve n to P5 ALEXANDER P. 511 KKERS ALBERT E. ELZY J SEPH 1. g @Ww, fii-Eorrze PATENTEDSEP 19 1912 SHEET 3 OF 4 Inventors ALEXANDER P. $TII KERS ALBERT E. E LZY JOSEPH yiczym B W 0 g Mali saw u [If 4 Inve nto rs ALEXANDER RSTIKKERS ALBERT E. ELZY J SEPH. -)C,YL

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PILOT VALVE ASSEMBLY FOR A SWITCH HEATER This invention relates in general to a switch' heater for railroads, and more particularly toa pilot burner assembly capable of providing pilot flame for the main burner of a switch heater. Heretofore, burners and switch heaters have been provided with various types of pilot burner assemblies, including spark ignition systems and flame ignition systems. While spark ignition systems work well, they require a considerable amount of hardware and controls, together with a supply of high voltage, all of which adds to the overall cost and installation problems. Flame ignition systems heretofore used do not require the hardware and controls neededfor spark ignition systems, but they have been unsatisfactory since they have been prone to sooting and blowout.

Switch heaters are located adjacent switches provided on railroad tracks, and are generally exposed to the elements. Accordingly, a satisfactory flame ignition system must include a pilot burner that will resist high winds, and provide continuous flame throughout the season. Inasmuch as switch heaters are located adjacent tracks, high winds are also generated by passing trains, and a pilot burner must be capable of standing such high winds.

The pilot burner of the present invention provides a flame for the main burner of a switch heater which resists blowout and avoids sooting. Excessive sooting can cause clogging of a pilot burner and ultimate malfunctioning. The pilot burner of the invention includes a combination shield and deflector that is used with the burner nozzle and is capable of providing a stabilized flame that prevents sooting and resists blowout. The shield portion of the combination shield and deflector unit extends from the burner nozzle and terminates in a flame dischargeopening which is partially covered by the deflector portion of the unit. The deflector portion covers about one-third the total exit area of the flame discharge opening, and the exit area is about equal to the flame exit area at the burner nozzle. The pilot burner assembly is adaptable for single or double jet burners.

It is therefore an object of the present invention to provide a new and improved pilot burner for a switch heater.

Another object of the present invention is in the provision of a new and improved pilot burner for a switch heater which resists blowout and prevents sootmg. I

Still another object of the present invention resides in the provision of a pilot burner of a combination shield and deflector unit which protects against blowout while still providing adequate combustion air and proper venting to avoid sooting.

A further object of the invention is to provide a pilot burner for a switch heater which is capable of being used in combination with single or double jet burners, and which provides a flame ignition system.

Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts, in which:

FIG. 1 is an elevational view of one form of the pilot burner according to the invention illustrated with a single jet burner for a switch heater, wherein some parts are broken away and some parts are in section for purposes of clarity;

FIG. 2 is a horizontal sectional view taken substantially along line 2-2 of FIG. 1;

FIG. 3 is a horizontal enlarged sectional view taken substantially along line 3-3 of FIG. 1; I

FIG. 4 is a vertical sectional view taken substantially along line 4-4 of FIG. 1;

FIG. 5 is aperspective view of the shield and deflector unit, and illustrating its association withthe pilot burner which is shown in dotted lines;

FIG. 6 is a partially exploded view of the pilot burner and showing one part in section for purposes of clarity;

FIG. 7 is a vertical elevational view of a double jet switch heater burner,.and the pilot burner according to the invention with some parts broken away to show underlying parts for purposes of clarity;

FIG. 8 is a perspective view of the deflector and shield unit and the main burner nozzle to illustrate the relationship therebetween, together with the pilot burner being shown in dotted lines;

FIG. 9 is a transverse enlarged sectional view taken substantially along line 9 --9 of FIG. 7;

FIG. 10 is a vertical sectional view taken substantiallyalong line 10-10-of FIG. 7, with some parts in section for purposes of clarity; and

FIG. 11 is a vertical sectional view taken substantially along line 11-1 1 of FIG. 7.

Referring now to the drawings and particularly to FIGS. 1 to 6, a heat generator for a switch heater is illustrated which includes generally a main burner as sembly 15, and a pilot burner assembly 16, wherein the pilot burner produces a flame for igniting the main burner. The pilot burner would be: manually lighted at the beginning of the season requiring use of the switch heater and would remain lit until the end of the season. The main burner would be controlled to be lit when needed. While it may be appreciated that the main and I pilot burners would be of the type capable of handling natural or synthetic gases as the fuel, itshould be appreciated that they may be conditioned to handle whatever fuel is available. The burners illustrated in the burner nozzle 18 includes an orifice 18a through which fuel is discharged from a chamber 18b into the one end of the burner tube 17. A fitting 18c is provided for attachment to a suitable source of fuel. The pilot burner 16 provides ignition for the burner nozzle 18. A vertically extending opening 20 is provided in the burner tube adjacent the burner nozzle and into which the pilot flame from the pilot burner assembly 16 is discharged. The lower end of the opening provides the entrance to the burner tube, while the upper end of the opening provides a vent for flue gases. The pilot burner assembly 16 is mounted on a bracket 23 within the pilot burner housing 19. In general, the pilot burner assembly includes a burner nozzle 24, a flame detector 25, and a combination shield and deflector unit 26.

The burner nozzle includes a cylindrical shell 27 having a flame retention member 28 secured therein, and within which is mounted a fuel nozzle 29. An orifice 30 within the fuel nozzle 29 regulates the fuel volume and is connected to an inlet fitting 31 which is in turn suitably connected to a source of fuel. The upper end of the cylindrical shell 27 extends upwardly from the flame retention member 28 and also acts as a flame retention member, and is provided with a plurality of circumferentially arranged flame retention holes 32. The holes supply additional combustion air to the flame of the pilot burner, which is necessary in order to permit proper and adequate combustion and prevent sooting. Other than the feature of providing the flame retention holes 32, the pilot burner nozzle 24 is conventional. The flame retention member 28 includes a plurality of small flame retention holes 33 and a large center hole 34. Air aspirating holes 35 are provided in the fuel nozzle 29 to assist in the discharge of fuel from the orifice 30.

The combination shield and deflector unit 26, which prevents blowout and assists in the prevention of sooting includes a shield portion 38 and a deflector portion 39. The shield portion is square in cross section and fits over the upper end of the pilot burner, and may be held thereon by frictional fit or by any other suitable means. As seen in FIG. 3, the shield portion 38 coacts with the cylindrical shell 27 of the burner to define four upstanding air channels 40, which are open at their bottom end to the atmosphere and allow air to pass outwardly to the flame retention holes 32 and to the upper end of the cylindrical shell 27 to assist in maintaining proper combustion of the fuel in the pilot burner. The upper end of the shield portion 26 defines a flame discharge opening 41 which is positioned at the inlet end of the opening 20 in the burner tube 17 as shown in FIG. 1. The shield 38 guards against blowout that may be caused by a wind passing laterally across the discharge end of the pilot burnernozzle.

The deflector 39 is in the form of a rectangular plate which extends from one of the side walls of the shield portion 38 over the flame discharge opening 41 to thereby restrict the size of the opening. Preferably, as shown, the deflector portion 39 is centrally positioned on the flame discharge opening 41 wherein the flame will go up and around it, and wherein any sudden downdraft will not blow out the pilot burner since the majority of the downdraft will be deflected from impinging directly on the burner nozzle. The size of the deflector portion 39 is such that it will cover about onethird the total width of the flame discharge opening 41, and therefore reduce the cross sectional area of the shield portion by about one-third. The flame exit area defined by the flame discharge opening 41, with the deflector in place, is about equal to the exit area at the burner nozzle 27. The combination shield and deflector unit also serves as flame retention means to assist in the proper combustion of the fuel and to thereby prevent sooting.

The product burner assembly of the present invention is also applicable for a dual jet burner used in switch heaters, such as illustrated in FIGS. 7 to 11. The main burner assembly is generally designated as 45,

while the pilot burner assembly is generally designated as 46.

Referring particularly to FIGS. 7, l0 and 11, the main burner assembly 45 includes an elongated horizontally extending burner tube 47, and an upstanding burner nozzle 48. A plurality of holes 49 are provided in the burner tube 47, and the burner nozzle 48 extends upwardly through an opening 50 formed in the burner tube. The burner nozzle 48 includes a nozzle head 51 mounted at the upper end of an inlet pipe 52. A pair of opposed fuel. orifices 53 are provided in the nozzle head 51 which distribute fuel in opposite directions along the interior of the burner tube 47. The orifices 53 are arranged coaxially with the burner tube so that the fuel discharge is central of the tube. The inlet pipe 52 of the burner nozzle 48 extends downwardly through the pilot burner housing 54, and is connected to a suitable source of fuel. The pilot burner assembly 46 is located within the pilot burner housing 54 and adjacent the main burner inlet pipe 52. Inasmuch as the burner tube 45 is provided with a plurality of combustion air openings v49, it is covered with panels 55 and 56.

The pilot burner assembly 46 includes a pilot burner and a combination shield and deflector unit 59. Since the pilot burner is identical to that used in the embodiment of FIGS. 1 to 6, the same reference numerals will be applied, and therefore the pilot burner nozzle is designated as 24. Similarly, a flame detector 25 is provided to detect whether the pilot burner is lit.

The combination shield and deflector unit 59 is similar to the unit 26 in that it is square in cross section and fits telescopically over the upper end of the pilot burner nozzle, as can be seen in FIG. 3. The unit is held in place by means of a strap bracket 60 wrapped around the main fuel burner inlet pipe 52 and the unit 46. The shield and deflector unit 59 includes a shield portion 61 and a deflector portion 62. The upper end of the shield portion 61 defines a flame discharge opening 63. An extension 64 coacts with the deflector unit in extending from the upper end of the shield portion 61 and coacts therewith to define the flame discharge opening 63 which includes a flame exit area about equal to the flame exit area at the pilot burner nozzle. The deflector 62 is of the same width as the width of the shield portion, and extends upward and diagonally over the upper end of the shield portion terminating 50 just above the extension 64, wherein the deflector prevents blowout of the flame from the pilot burner nozzle as a result of downdrafts. Additionally, the deflector 62 deflects the pilot flame upwardly and therearound so that it will be split .for the use of each orifice 53 of the main burner nozzle head 51. The shield and deflector unit facilitates combustion of the gases and prevents the buildup of carbon with the burner tube. Otherwise the operation is the same as the embodiment of FIGS. 1 to 6. In order to assure proper ignition of the main burner by the pilot burner when the main burner is turned on, ignition scoops 68 and channel-shaped troughs 69 are provided in the burner tube 47, as particularly shown in FIGS. 7 and 10. The

channel-shaped troughs are aligned with the fuel discharge from the orifices 53, and with the split pilot burner flame being discharged from the pilot burner opening 63. The scoops or deflectors 68 are arranged within the channel-shaped troughs 69 to deflect back fuel discharge from the orifices 53 to the area of the pilot burner flame to enable ignition. It should be appreciated that the fuel is discharged under a high pressure and therefore the ignition scoops 68 and channelshaped troughs 69 are necessary to allow the single pilot flame to properly ignite the fuel discharge from each of the orifices.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention, but it is understood that this application is to be limited only by the scope of the appended claims.

This invention is hereby claimed as follows:

1. A pilot burner assembly for a switch heater to produce a pilot flame for lighting a main burner, the assembly including a burner connected to a fuel source at one end and having a nozzle at the other end, the improvement in a shield and deflector unit mounted on the nozzle, said unit including a rectangular in crosssection tubular shield portion wrapped around the burner and extending from the nozzle end, said nozzle end of the burner being circular in cross-section, the outer end of the shield portion terminating in a flame discharge opening, and a deflector portion extending over the flame discharge opening coacting with the shield portion to aid flame retention and prevent blowout.

2. The combination as defined in claim 1, and flame retention holes in said nozzle adjacent the terminal end thereof providing combustion air to the flame.

3. A pilot burner assembly for a switch heater to produce a pilot flame for lighting a main burner, the assembly including a burner connected to a fuel source at one end and having a nozzle at the other-end, the improvement in a shield and deflector unit mounted on the nozzle, said unit including a tubular shield portion wrapped around the burner and extending from the nozzle end, the outer end of the shield portion terminating in a flame discharge opening, and a deflector portion extending over and covering about one-third of the flame discharge opening coacting with the shield portion to aid flame retention and prevent blowout.

4. The combination as defined in claim 3, wherein the shield cross section is sized so that the flame exit area at the flame discharge opening is about equal to the flame exit area at the nozzle end of the burner.

5. In a switch heater, a single jet burner including an elongated horizontally extending burner tube, a single jet fuel nozzle at one end of the tube, and an opening extending upwardly through the tube adjacent the fuel nozzle, the improvement in a pilot burner assembly for producing a pilot flame in said opening, said assembly comprising a burner connected to a fuel source at one end and having a nozzle at the other end, and a shield and deflector unit mounted on the nozzle, said unit including a tubular shield portion wrapped around the burner and extending from the nozzle end and terminating in a flame discharge opening in the proximity of the burner tube opening, the nozzle end of the burner being circular in cross section and the shield portion being square in cross section, flame retention holes in circumferentially spaced relation at the discharge end of the nozzle within the shield portion an rovidin combust'o air t the nozzle, channels deiined betw en the shiel d portion and nozzle to per mit air to travel to the flame retention holes and the discharge end of the nozzle, and a deflector portion extending over the flame discharge opening of the shield portion.

6. The combination as defined in claim 5, wherein the deflector portion is sized to cover about one-third the area of the flame discharge opening.

7. In a switch heater, a double jet. burner including an elongated horizontally extending burner tube, a double jet fuel nozzle centrally of the tube for discharging fuel in opposite directions, the jets being coaxial with the tube, the improvement in a pilot burner assembly extending vertically and producing a pilot flame adjacent the double jet fuel nozzle, said assembly comprising a burner connected to a fuel source at one end and having a nozzle at the other end, and a shield and deflector unit mounted on the nozzle, said unit including a tubular shield portion wrapped around the burner and extending from the noule end and terminating in a flame discharge opening adjacent the double jet fuel nozzle, the nozzle end of the burner being circular in cross section and the shield portion being square in cross section, flame retention holes in circumferentially spaced relation at the discharge end of the nozzle within the shield portion and providing combustion air to the nozzle, channels defined between the shield portion and nozzle to permit air to travel to the flame retention holes and the discharge end of the nozzle, and a deflector portion extending over the flame discharge opening of the shield portion.

8. The combination defined in claim 7, wherein the deflector portion is sized and positioned to split the flame and ignite the fuel from each jet of the nozzle.

9. The combination as defined in claim 8, and ignition scoops and channels in said burner tube reducing the velocity of a small part of the fuel discharge adjacent the pilot burner flame to enable ignition. 

1. A pilot burner assembly for a switch heater to produce a pilot flame for lighting a main burner, the assembly including a burner connected to a fuel source at one end and having a nozzle at the other end, the improvement in a shield and deflector unit mounted on the nozzle, said unit including a rectangular in cross-section tubular shield portion wrapped around the burner and extending from the nozzle end, said nozzle end of the burner being circular in cross-section, the outer end of the shield portion terminating in a flame discharge opening, and a deflector portion extending over the flame discharge opening coacting with the shield portion to aid flame retention and prevent blowout.
 2. The combination as defined in claim 1, and flame retention holes in said nozzle adjacent the terminal end thereof providing combustion air to the fLame.
 3. A pilot burner assembly for a switch heater to produce a pilot flame for lighting a main burner, the assembly including a burner connected to a fuel source at one end and having a nozzle at the other end, the improvement in a shield and deflector unit mounted on the nozzle, said unit including a tubular shield portion wrapped around the burner and extending from the nozzle end, the outer end of the shield portion terminating in a flame discharge opening, and a deflector portion extending over and covering about one-third of the flame discharge opening coacting with the shield portion to aid flame retention and prevent blowout.
 4. The combination as defined in claim 3, wherein the shield cross section is sized so that the flame exit area at the flame discharge opening is about equal to the flame exit area at the nozzle end of the burner.
 5. In a switch heater, a single jet burner including an elongated horizontally extending burner tube, a single jet fuel nozzle at one end of the tube, and an opening extending upwardly through the tube adjacent the fuel nozzle, the improvement in a pilot burner assembly for producing a pilot flame in said opening, said assembly comprising a burner connected to a fuel source at one end and having a nozzle at the other end, and a shield and deflector unit mounted on the nozzle, said unit including a tubular shield portion wrapped around the burner and extending from the nozzle end and terminating in a flame discharge opening in the proximity of the burner tube opening, the nozzle end of the burner being circular in cross section and the shield portion being square in cross section, flame retention holes in circumferentially spaced relation at the discharge end of the nozzle within the shield portion and providing combustion air to the nozzle, channels defined between the shield portion and nozzle to permit air to travel to the flame retention holes and the discharge end of the nozzle, and a deflector portion extending over the flame discharge opening of the shield portion.
 6. The combination as defined in claim 5, wherein the deflector portion is sized to cover about one-third the area of the flame discharge opening.
 7. In a switch heater, a double jet burner including an elongated horizontally extending burner tube, a double jet fuel nozzle centrally of the tube for discharging fuel in opposite directions, the jets being coaxial with the tube, the improvement in a pilot burner assembly extending vertically and producing a pilot flame adjacent the double jet fuel nozzle, said assembly comprising a burner connected to a fuel source at one end and having a nozzle at the other end, and a shield and deflector unit mounted on the nozzle, said unit including a tubular shield portion wrapped around the burner and extending from the nozzle end and terminating in a flame discharge opening adjacent the double jet fuel nozzle, the nozzle end of the burner being circular in cross section and the shield portion being square in cross section, flame retention holes in circumferentially spaced relation at the discharge end of the nozzle within the shield portion and providing combustion air to the nozzle, channels defined between the shield portion and nozzle to permit air to travel to the flame retention holes and the discharge end of the nozzle, and a deflector portion extending over the flame discharge opening of the shield portion.
 8. The combination defined in claim 7, wherein the deflector portion is sized and positioned to split the flame and ignite the fuel from each jet of the nozzle.
 9. The combination as defined in claim 8, and ignition scoops and channels in said burner tube reducing the velocity of a small part of the fuel discharge adjacent the pilot burner flame to enable ignition. 